Are these tubes useful for amps?

[rafe]

6x4wa, 6j6w, 6be6, 6aw8a, 6x8, 6sn7gtb (not Russian), OA2 They are all NOS in boxes USA German Great Brit. I have a lot of the first 2 types   I am not familiar with most of them and I am curious if anyone has seen them appearing in amps? Thanks in advance

[PRR]

Look them up on Google and at Frank's.

But in general: the research and experimentation to optimize a new tube for musical purpose exceeds the value of a tube you already know what to do with.

[kagliostro]

For 6x4wa - 6j6w - 6sn7gtb - OA2

I can hazzard with not much hazzard that you can use it

Some old radio used 6x4 rectifiers, there is an homemade amp called 7 cylinder that uses 6j6 as Pharaphase PI, many old guitar amp schematics show the use of 6sn7 tube, OA2 are used sometime in old tube schematics (may be I remember a modulator for RF transmitter)

for the remaining tubes I don't know, you must go for an internet search

Franco

[rafe]

I was curious if any odd-ball models had used them in the past . I have 9 of the 6x4wa's and 8 of the 6j6w's both are NOS from the early 50's might be useful to radio enthusiasts. I grabbed them in a package deal with the 2 sets of matched mullards I asked about cleaning. He had a lot of loose tube also, that I passed on (Hundreds)
I will look at the 7 cylinder if I can find it.Thanks PS. I did look online and I think I might have seen the 6x4 in tube tape recorders and old high fi's

[rafe]

P.S. yeah I have seen the 6x4 ! in My Kalamazoo model 2 the model 1 also uses it! Probably some other ones out there. I had forgotten about having to buy a 6x4 when I acquired that model 2 a couple years ago!

[Electron Tornado]

I used a 6X4 in a 3 watt tube amp I built. Works great.

[sluckey]

I used a 6X4 in a 3 watt tube amp I built. Works great.

Just a funny thought... It takes 3.78 watts just to heat that 6X4.   

[scstill]

Just a funny thought... It takes 3.78 watts just to heat that 6X4.   

Better than a 10w 5y3 in a 5w champ.

BTW - I love the 6SN7 twin diode as Preamp and PI tube. Very musical IMO...

[Electron Tornado]

BTW - I love the 6SN7 twin diode as Preamp and PI tube. Very musical IMO...

I wonder how the 6CG7 would compare with the 6SN7 (since I have 2 or 3 of the former). Both have the same amplification factor.

[HotBluePlates]

I wonder how the 6CG7 would compare with the 6SN7 (since I have 2 or 3 of the former). Both have the same amplification factor.

IIRC, 6CG7 is a 6SN7 slimmed down to fit in a miniature bottle.  As for sound, I have no idea.

... 6sn7gtb (not Russian) ...

I was curious if any odd-ball models had used them in the past . ...

I have an early Ampeg Reverberocket that uses 6SN7 in the preamp (along with 6SL7).

Someone else's video of this amp's sound (skip to 1:52):

[scstill]

I wonder how the 6CG7 would compare with the 6SN7 (since I have 2 or 3 of the former). Both have the same amplification factor.

Here is a great resource. Claims the 6CG7 is successor to 6SN7GT
https://www.radiomuseum.org/tubes/tube_6sn7gt.html

[SoundmasterG]

6CG7's sound great! I wish they were still made in good quality like the good old days.


6SN7's sound great too, though many people these days don't like either of these tubes much for guitar amps as they are lower gain compared to the usual 12AX7.


The OA2 was used as a regulator tube in power supplies. There are some applications you might be able to use those in these days, but probably not for a guitar amp where you want touch response and want the power supply to sag.

Greg

[kagliostro]

SAG don't "affect" SE Amps so there you haven't that limitation

EDIT: here is an example of use for the stabilizer tube (OA2) here a VR-150

Here the article about
https://el34world.com/Forum/index.php?action=dlattach;topic=11766.0;attach=24010



Franco

[Electron Tornado]

6CG7's sound great! I wish they were still made in good quality like the good old days.


6SN7's sound great too, though many people these days don't like either of these tubes much for guitar amps as they are lower gain compared to the usual 12AX7.

According to Merlin Blencowe, the 6SN7 performed well when used as a cascode. Has anyone tried this with either the 6SN7 or the 6CG7?

[HotBluePlates]

... when used as a cascode. Has anyone tried this ...

About 15v years ago, I was all excited about the cascode ("More gain!!!")

Others here helped me see that a cascode is merely "spending 2 triode sections to get 1 pentode section" and that the gain of the cascaded triode sections is greater than that of the cascode or pentode.

I couldn't find a job for the cascode that wasn't performed just as well (or better) by a pentode or 2 triodes.  So I still haven't gotten around to trying the cascode.

[shooter]

my 6sn7 build, went into the wild, never heard from it since 


should be a thread on the build, was to far back to recall details.
I've used and liked them in Audio builds

[scstill]

A recent all octal, two 6SN7 design that sounds really good. Low Noise.
Been playing it recently with my Gretsch Baritone.
Very musical sounding amp with great tone and sustain.
https://stillampd.com/weekender